2. Tennis Practice your backhand or volley in a Stroke of the Week mini-course at the Midtown Tennis Club for $15. Novices get the nuts and bolts from four one-hour lessons for $120. (341 Eighth Avenue, near 27th Street; 212-989-8572.)

4. Wall Climbing The Central Park course goes over the basics for first-time and advanced climbers ($200, and no permit required). For you Triple-Xers with abs of steel, a climb on the wall at the Rock Health and Fitness Club in Queens is your best bet ($20). (North Meadow Recreation Center: mid-park at 97th Street; 212-348-4867; the Rock in Queens: 22-15 31st Street, Astoria; 718-204-1400.)

5. Kayaking New York Kayak Company offers hourlong lessons at any skill level (starting at $80; includes gear) on the Hudson River—which is so clean these days you probably won’t run across anything nasty. (South side of Pier 40, between Houston and West Streets; 800-KAYAK99.)